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Journal of Thermal Analysis and Calorimetry
Authors: Rosali Ferreira da Silva, Flávia Morais de Medeiros, T. Nascimento, R. Macêdo, and P. Neto

Abstract  

The object of the present work is to study the thermal characteristics of indinavir sulfate and to evaluate the quality of the raw materials. Indinavir A, B, C and reference samples were obtained from different suppliers and submitted to TG, DSC and DSC-photovisual analyses. TG/DTG curves indicated a desolvation and dehydration processes and were confirmed by DSC. According to the DSC curves the fusion took place at about 141–142°C for indinavir C and Reference sample B and about 146–149°C for the others. DSC-photovisual showed insoluble raw materials for indinavir C at 160°C. Indinavir sulfate is highly hygroscopic drug which requires attention during storage and manufacture by pharmaceutical industry.

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Journal of Thermal Analysis and Calorimetry
Authors: D. Giron, Ch. Goldbronn, M. Mutz, S. Pfeffer, Ph. Piechon, and Ph. Schwab

Abstract  

Manufacturing processes may involve the presence of water in the crystallization of the drug substance or in manufacturing or in the composition of the drug product through excipients. Dehydration steps may occur in drying, milling, mixing and tabletting processes. Furthermore, drug substances and drug products are submitted to different temperatures and relative humidities, due to various climatic conditions giving rise to unexpected hydration or dehydration aging phenomena. Therefore the manufacture and the characterization of hydrates is part of the study of the physical properties of drug substances. Several hydrates and even polymorphic forms thereof can be encountered. Upon dehydration crystal hydrates may retain more or less their original crystal structure, they can lose crystallinity and give anamorphous phase, they can transform to crystalline less hydrated forms or to crystalline anhydrous forms. The proper understanding of the complex polyphasic systemhydrates–polymorphs–amorphous state needs several analytical methods. The use of techniques such as DSC-TG, TG-MS, sorption-desorption isotherms, sub-ambient experiments, X-ray diffraction combined with temperature or moisture changes as well as crystal structure and crystal modelling in addition to solubilities and dissolution experiments make interpretation and quantitation easier as demonstrated with some typical examples.

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Abstract  

Thermal analysis methods are well-established techniques in research laboratories of pharmaceutical industry. The robustness and sensitivity of instrumentation, the introduction of automation and of reliable software according to the industrial needs widened considerably the areas of applications in the last decade. Calibration of instruments and validation of results follow the state of the art of cGMP as for other analytical techniques. Thermal analysis techniques are especially useful for the study of the behavior of the poly-phasic systems drug substances and excipients and find a unique place for new delivery systems. Since change of temperature and moisture occur by processing and storage, changes of the solid state may have a considerable effect on activity, toxicity and stability of compounds. Current requirements of the International Conference of Harmonisation for the characterization and the quantitation of polymorphism in new entities re-enforce the position of thermal analysis techniques. This challenging task needs the use of complementary methods. Combined techniques and microcalorimetry demonstrate their advantages. This article reviews the current use of thermal analysis and combined techniques in research and development and in production. The advantage of commercially coupled techniques to thermogravimetry is emphasized with some examples.

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Journal of Thermal Analysis and Calorimetry
Authors: Giovanna Bruni, Franco Sartor, Vittorio Berbenni, Chiara Milanese, Mariarosa Maietta, Dionigio Franchi, and Amedeo Marini

substance, or, (c) yielding a new crystal with fewer or no solvent/water molecules [ 6 – 13 ]. At room temperature (r.t.), paroxetine hydrochloride can be obtained (with different synthesis procedures) in two crystalline forms, called pseudo-polymorphs

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different solid phases that may occur during crystallization and pharmaceutical formulation processes, i.e. polymorphs, pseudo-polymorphism, solvates, desolvated solvates and amorphous materials is therefore advisable for both drugs and excipients. It is

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, E . Crystalline modifications and polymorphism changes during drug manufacture . Ann Pharm Fr . 2002 ; 60 : 161 – 176 . 13. Giron , D . Investigation of polymorphism and pseudo-polymorphism

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of batch crystallization processes . Org Proc Res Dev . 2009 . http://dx.doi.org/10.1021/op900019b . 23. Giron D . Investigations of polymorphism and pseudo-polymorphism

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Journal of Thermal Analysis and Calorimetry
Authors: Martin Tjahjono, Martin Karl Schreyer, Liangfeng Guo, and Marc Garland

industrial crystallization, Chap. 2 . Boston : Butterworth-Heinemann ; 2002 . 11. Giron , D . 2001 Investigations of polymorphism and pseudo-polymorphism in pharmaceuticals by combined

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